Trouble spots

New research from institutions including the New York University School of Medicine shows factors such as genetic variations and family history may play as big a part in causing melanoma as blistering sunburn.

Simply put, taking preventative measures against ultraviolet rays is not enough. Instead, learning how to examine your own skin and identify suspicious moles early could be a life-saver.

With her red hair and pale skin, 40-year-old volunteer worker Kirsty Thomas had always taken care in the hot sun in Australia, where she grew up.

'The Slip Slop Slap campaign had only just started in the 1980s, but my father was a GP and very vigilant about sun protection,' Thomas says.

'It was drummed into me from an early age I should always wear a hat and sunscreen, and stay out of the sun in the middle of the day. So when I discovered a tiny new black mole on the top of my left foot - the size of a large match head - I didn't believe it was anything serious; I'd always been so careful.

'I showed my dad and he made me an appointment with a melanoma clinic immediately. The next day, I was in hospital for a major excision and skin graft; fortunately, the melanoma was less than 3mm deep and hadn't spread to my lymph nodes. Needless to say, today I'm religious about regularly checking my skin.'

The main thing is to catch cancerous moles in their early stages before they invade the deeper layers of the skin, says dermatologist Gavin Chan from SkinCentral.

'If we surgically remove a melanoma before it has spread, the chance of cure is much higher; with early detection and proper treatment the cure rate is about 95 per cent. Everyone should learn to perform a skin self-examination to identify suspicious lesions or skin changes. These should then be evaluated by a dermatologist or physician. We also recommend an annual skin examination for those with risk factors, where a doctor can help screen your skin from head to toe, and identify anything that looks suspicious and requires a biopsy.'

According to Chan, there are sophisticated tools to help detect skin abnormalities in the earliest stages. Dermoscopy, for example, is a non-invasive technique that uses a hand-held magnifying device with a light source to evaluate skin lesions.

'Dermoscopy allows us to see into the deeper layers of the skin and detect pigmentation patterns and skin structures that cannot be seen with the naked eye. Studies show using dermoscopy improves diagnostic accuracy for melanoma and suggests a reduced rate in the excision of benign lesions,' says Chan.

Australia - the skin cancer hub of the world - is leading the way in automated machine detection, which gives a risk analysis of how suspicious a mole is. The machine can image a mole based on computer analytic techniques to see if it is high or low risk.

In Hong Kong, the SolarScan is available at the Hong Kong Skin Cancer Diagnostic Unit (HKSCDU) in Central. It takes magnified digital photographs of the skin then analyses them using a computer.

A spokesman for HKSCDU says: 'The images are calibrated and examined using sophisticated mathematical tools developed by scientists from the Sydney Melanoma Unit and Polartechnics in Australia. The results from each test are then compared against a clinical database developed by the Sydney Melanoma Unit, and give an estimation of the risk/likelihood of the lesion being a melanoma.'

For people at high risk of melanoma, including those with many moles (more than 50), atypical or dysplastic moles (meaning an abnormal development or growth), fair skin that has been severely sunburned, family history or previous history of melanoma, Chan suggests mole mapping, or total body photography as a useful tool in any melanoma surveillance programme. This entails photography of the entire body, with close-up macro images of areas of concern. These images can then be referred back to at a later date, to determine whether a lesion of concern is new or has changed.

'I had a couple of dysplastic naevi [moles with an unusual colour and shape] on my shoulder that were removed a few years ago. Because they were on my back I didn't realise how much they were changing,' says 41-year-old photographer, Susan Shaw.

'I now have my entire body mole mapped every 12 months. They use a pen to draw a circle around the moles they're concerned about, and they measure them with a ruler. They use this as a benchmark when I return the following year. It's a bit embarrassing being photographed in your underwear, but I do feel a lot more confident about the health of my skin.' Chan says the incidence of skin cancer is on the rise across the globe. This is especially true in Australia - where over the last 10 years the incidence has jumped to 16 per cent in males and 24 per cent in females - but rising statistics are not limited to Australia.

In Britain, a recent study carried out by Cancer Research UK showed malignant melanoma has increased more than any other common cancer in the past 30 years.

According to Chan, although melanoma occurs much less often among Asians compared with Caucasians, the results of a local Hong Kong study estimate rising incidence rates in the future, related to an ageing population.

The most common melanoma for Asian skin types is acral lentiginous melanoma (ALM). While it constitutes only 5 per cent of all diagnosed melanomas globally, it accounts for half of melanomas that occur in Asians and those with dark skin. ALM is sometimes referred to as 'hidden melanoma' as lesions are found on parts of the body not easily examined, including palms, soles, under the fingernails or mucous membranes (such as those that line the mouth, nose and female genitals).

'ALM is often missed until it is advanced, because it can look like a bruise or nail streak in the early stages,' says Chan.

Another misconception is to equate 'skin cancer' with melanoma. Melanoma is the most deadly, but there are several other types of skin cancer that, if left untreated, can also be life threatening. To add to the confusion, skin cancers are not necessarily pigmented - they may be flesh, pink or red, or may be present as patches, scaly bumps or even look like warts - meaning they are more difficult to identify.

'Squamous cell carcinoma, a skin tumour of the squamous cells, has the potential to grow quickly and can spread to other parts of the body,' says Chan.

'Basal cell carcinoma, on the other hand, grows slowly and locally, and although it rarely spreads it can grow quite large over time.'

Australian radiologist Tony Griffin has had personal experience of squamous cell carcinoma. 'I noticed a flesh-coloured, scaly lesion on the edge of my left ear that kept coming back even after I had picked it off. I consulted my GP who performed a biopsy. It was a malignant squamous cell cancer that required excision; I also needed a small skin graft to cover it.'

Griffin says the changes your doctor would look for in moles include: development of irregular margins, increase in size or pigmentation, changes in the skin around the mole and ulceration.

'As a doctor, I knew the lesion was abnormal, but as a lay person I may not have. Then the challenge for your doctor is to distinguish potentially lethal moles from the rest, which, with rare exceptions, are almost always benign.'

All the experts say you must keep a eye on your skin and take precautions when out in the sun.

'Use a broad spectrum sunscreen protecting against both UVB and UVA with a sun protection factor [SPF] of 15 or above, regularly reapply every two hours, try to avoid the sun between 10am and 3pm, and use sun protective clothing,' says Chan.

'If you have any suspicious or changing skin lesions of concern, seek expert advice. Regular self-examination by a dermatologist or physician can lead to early detection and successful treatment of most skin cancers.'